Alarm device for internalcombustion engines



L. B. GORE July 31,1945.

ALARM DEVICE FOR INTERNAL-COMBUSTION ENGINES Filed March 7, 1944 INVENTUR Lloyd B. Gore mmfimge g ATTORNEYS Patented July 31, 1945 UNITED STATES PATENT oFFica ALARM DEVICE FOR INTERNAL- COMBUSTION ENGINES Lloyd Ballard Gore, Vancouver, British Columbia,

. Canada Application March 7, 1944, Serial No. 525,383

- ried on a supporting block 25 countersunk in the 7 Claims.

This invention relates to improvements in alarm device for internal combustion engines and the objects are to provide asimple and effective device for this purpose to better perform the function required of it.

The improvement relates to the type of device in which the oil pressure is designed to operate against a spring controlled diaphragm whose movement is caused to control a switch which, in turn, controls an electrical alarm device.

Further objects of the invention are to improve the construction of the diaphragm-containing member and means for supporting and mounting the contact points and protecting them from interference. The invention consists essentially of the improved construction and arrangement of parts as hereinafter described in detail in the accompanying specification and drawing.

In the drawing:

Figure 1 is a section elevation of an embodiment of the invention;

Figure 2 is a sectional plan on the line 2-2 of Figure 1;

Figure 3 is a sectional plan on the line 3-3 of Figure 1;

Figure 4 is a diagrammatic view illustrating the circuit connections.

In the drawing like characters of reference indicate corresponding parts in all the figures.

Referring to the drawing A indicates the body portion of the device in which the diaphragm B is mounted, the body portion comprising a lower tubular sleeve section Ill and an upper larger cylindrical section II containing the diaphragm chamber i2. The diaphragm B, which may be conveniently made of thin spring metal, extends over the chamber i2, being held in position by means of a ring l3 held in place by a plurality of screws l4.

Extending through the diaphragm is a stem C, partially screw-threaded, and held with respect to the diaphragm by nuts I! and it on opposite sides of the diaphragm. The stem is adapted to control the switch D mounted in a switch block H on top of the body portion having a peripheral flange I3 which extends over the side of the ring 13 and hold the block in place.

The switch D includes a spring contact member i3 mounted on a supporting block countersunk in block i1 and connected to a terminal member 2! which extends through the ,block I! and is provided on the exterior with a binding post 22. The spring contact member D carries a contact point 23, preferably of tungsten steel, adapted to engage a corresponding point 24 carblock I1 and connected to a contact member 28 having an exterior binding post 21.

' members 2| and26 are preferably firmly soldered to the blocks 20 and so that they will remain firmly in place.

The stem C carries a disc-like tappet member 28 at its upper end designed to engage the upper end of the contact point 23 on the spring contact member i9 whereby the contacts are forced together when the tappet member is in lbwermost position. Associated with'the stem 0 is a spiral spring 29 tending to force thesame to lowermost position. This spring extends within a cylindrical recess 30 in the sleeve I'O abutting at one end the base 31 of the recess, and at the other the ring 32 extends around the sleeve, fitting closely to the walls or the outer enlarged portion 33 of the recess. The ring 32 is held in adjusted position on the stem by means of nuts 34 and 35 which engage the screw-threaded end of the sleeve. The.

inner nut is separated from the ring .32 by one or more washers 36 by which the spring pressure may be adjusted.

To prevent tampering with the switch a cover chamber-'E'is provided adapted to extend over the parts of the switch block H, the cover being maintained in position by screws 36 which extendthrough it into the switch block. In order to prevent tampering with the switch a seal 31 may be provided connected to one oi. the screws 38 and tea screw or projection 38 on the cover.

In the circuit diagram in Figure 4, F represents an internal combustion engine, G a pump and H the oil circulating system including a gauge 33. I

indicates an alarm device of the-form shown in Figures 1-3, the terminals from which are connected to an electric circuit 40 including a battery 4!, an audible signal 42 such as a bell and a light signal 43 and a switch 44. The switch 44 is so positioned that it will be closed when the throttle is open during the starting or the engine. This completes the circuit causing the light 43 to be illuminated and the bell 42 rung until the oil pressure reaches normal, when the contacts Contact Although the alarm device referred to is described in connection with the lubricating system of an internal combustion engine, it will be obvious that it may be used on any piece 01 machinery where pressure lubrication is employed. Furthermore, it will be observed that as the pressure enters the chamber I! through the ports 48 and 4B, the pressure of the oil will compress the air in the ports and chamber, with the result that the oil never comes in contact with the diaphragm B. This is an important advantage since the viscosity of the oil will not affect the movement or resllinecy of the diaphragm. Where oil has an opportunity to contact with the diaphragm, the variation of the viscosity of the oil will eflect the sluggishness or otherwise or the diaphragm.

Various modifications may be made in this invention without departing from the spirit thereof or the scope or the claims, and, therefore, the

exact i'orms shown are to be taken as illustrative only and not in a limiting sense, and it is desired that only such limitations shall be placed thereon as are disclosed in the prior art or are set forth in the accompanying claims.

What I claim as my invention is:

1. An alarm system for use with fluid pressure systems, comprising a chamber, a diaphragm dividing said chamber, means ior admitting fluid to one end of said chamber, a stem passing through said diaphragm and fixed thereto, a switch block defining one end or said chamber, one end of said stem passing through said switch block and having fixed on it a member adapted to operate an electrical switch mounted between said switch block and said member upon movement of said diaphragm due to changes of fluid pressure in said chamber, said electrical switch comprising at least two terminals connected in an electrical circuit and carried on said switch block, and means tor making an electrical contact between said terminals, said means being urged by spring pressure to open said circuit and being engaged by said member and actuated against said spring pressure to make said electrical contact and close said circuit.

2. The device as claimed in claim 1 in which the switch comprises terminals countersunk in the switch block having external binding posts.

3. The device as claimed in claim 1 in which the switch comprises a spring contact member connected to one of said terminals and having a tungsten point adapted to engage a corresponding contact point mounted in the switch block in connection with the other of said terminals.

4. An alarm system as defined in claim 1 comprising a cover enclosing said member, said switch block and said electrical switch.

5. The device as claimed in claim 1 in which a cover is provided extending over the switch and in which sealing means extend between the cover and switch block.

6. An alarm system for use with fluid pressure systems comprising a chamber, a diaphragm dividing said chamber, a switch block defining one end of said chamber, means for admitting fluid to the other end of said chamber, a stem passing through said diaphragm and afilxed thereto, one end of said stem passing through said switch block and carrying means for operating an electrical switch, and means for adjusting the pressure at which the alarm operates comprising an elongated recess surrounding a portion of said stern, a coil spring housed in said recess and around said stem, and means on said stem adapted to compress said spring against the end or said recess nearer to said diaphragm to urge said stem in a direction opposite to that eflected by said diaphragm under influence oi fluid pressure in said chamber, said means adapted to compress said spring being adjustable along the length of said stem to vary compression of said spring.

7. An alarm system for use with fluid pressure systems as defined in claim 6, comprising a sleeve carried by said stem and moveable axially thereon; and at least one nut threaded on a portion of said stem, said sleeve engaging said nut at one end and at the other engaging said spring.

LLOYD BALLARD GORE. 

